Integrins are a family of heterodimeric
glycoproteins involved in bidirectional cell signaling that participate in the regulation of cell shape, adhesion, migration, survival and proliferation. The
integrin α1β1 is known to be involved in RAS/ERK proliferative pathway activation and plays an important role in fibroblast proliferation. In the small intestine, the
integrin α1 subunit is present in the crypt proliferative compartment and absent in the villus. We have recently shown that the
integrin α1
protein and transcript (ITGA1) are present in a large proportion of
colorectal cancers (CRC) and that their expression is controlled by the MYC oncogenic factor. Considering that α1 subunit/ITGA1 expression is correlated with MYC in more than 70% of
colon adenocarcinomas, we postulated that the
integrin α1β1 has a pro-tumoral contribution to CRC. In HT29, T84 and SW480 CRC cells, α1 subunit/ITGA1 knockdown resulted in a reduction of cell proliferation associated with an impaired resistance to anoikis and an altered cell migration in HT29 and T84 cells. Moreover,
tumor development in xenografts was reduced in HT29 and T84 sh-ITGA1 cells, associated with extensive
necrosis, a low mitotic index and a reduced number of blood vessels. Our results show that α1β1 is involved in
tumor cell proliferation, survival and migration. This finding suggests that α1β1 contributes to CRC progression.